Pleiotropic Action of Selenium in the Prevention and Treatment of Cancer, and Related Diseases

This book will cover topics related to the preparation and use of heterogeneous catalytic systems for the transformation of renewable sources, as well as of materials deriving from agro-industrial wastes and by-products. At the same time, the ever-increasing importance of bioproducts, due to the acceptance and request of consumers, makes the upgrade of biomass into chemicals and materials not only an environmental issue, but also an economical advantage

Numerical analysis of the partial collapse of a twin-tubes tunnel

On the 1st of January 2014, the left tunnel of the twin-tube situated in the eastern part of the East-West Algerian highway, still under construction, was affected by a partial collapse, which induced significant damages over a distance of 120 m. In this paper, a 3D numerical simulation was used to investigate the loading state and deformation pattern governing the structure during the partial collapse. The results shows that the failure was mainly triggered by a large displacements of the primary lining which was applied to the left tunnel without final reinforcements, and was insufficient to counteract the applied stresses. Practical recommendations that could be drawn from this case are suggested

Atomic Force Microscope: Modeling, Simulations, and Experiments

The quality of atomic force microscope (AFM) data strongly depends on scan and controller parameters. Data artifacts can result from poor dynamic response of the instrument. In order to achieve reliable data, dynamic interactions between AFM components need to be well understood and controlled. In this paper we present a summary of our work in this direction. It includes models for the probe-sample interaction, scanner lateral and longitudinal dynamics, scanner creep, and cantilever dynamics. The models were used to study the effect of scan parameters on the system dynamics. Simulation results for both frequency response and imaging were presented. Experimental results were given supporting the simulations and demonstrating the competence of the models. The results within will be used to develop algorithms that allow automated choice of key system parameters, guaranteeing reliable and artifact-free data for any given operating condition (sample, cantilever, environment). Consequently, expanding the AFM capabilities and permitting its use in a wider range of applications.Singapore-MIT Alliance (SMA

Impacts of Industrial Baseline Errors on Costs and Social Welfare in the Demand Side Management of Day-Ahead Wholesale Markets

Demand Side Management (DSM) has been recognized for its potential to counteract the intermittent nature of renewable energy, increase system efficiency, and reduce system costs. While the popular approach among academia adopts a social welfare maximization formulation, the industrial practice in the United States electricity market compensates customers according to their load reduction from a predefined electricity consumption baseline that would have occurred without DSM. This paper is an extension of a previous paper studying the differences between the industrial & academic approach to dispatching demands. In the previous paper, the comparison of the two models showed that while the social welfare model uses a stochastic net load composed of two terms, the industrial DSM model uses a stochastic net load composed of three terms including the additional baseline term. That work showed that the academic and industrial optimization method have the same dispatch result in the absence of baseline errors given the proper reconciliation of their respective cost functions. DSM participants, however, and very much unfortunately, are likely to manipulate the baseline in order to receive greater financial compensation. This paper now seeks to study the impacts of erroneous industrial baselines in a day-ahead wholesale market context. Using the same system configuration and mathematical formalism, the industrial model is compared to the social welfare model. The erroneous baseline is shown to result in a different and more importantly costlier dispatch. It is also likely to require more control activity in subsequent layers of enterprise control. Thus an erroneous baseline is likely to increase system costs and overestimate the potential for social welfare improvements

Effectiveness of Composite CFRP Confinement on Very Slender Reinforced Concrete Columns

This research work is based on an experimental study resulting from tests carried out on six square-section slender reinforced concrete columns. The columns were confined by single-layer wraps of carbon fiber composites. They were tested under eccentric compression loading, to study the effects of confinement by the carbon fiber composite on resistance loading, rigidity, ductility and slender column behavior in genera

An Enterprise Control Assessment Method for Variable Energy Resource-Induced Power System Imbalances--Part I: Methodology

In recent years, an extensive academic and industrial literature has been developed to determine how much such variable energy resources (VERs) may be integrated and how to best mitigate their impacts. While certainly insightful within the context of their application, many integration studies have methodological limitations in that they are case specific, address a single control function of power grid balancing operations, and are often not validated by simulation. This paper presents a holistic method for the assessment of power grid imbalances induced by VERs based upon the concept of enterprise control. It consists within a single package a three-layer enterprise control simulator which includes most of the balancing operation functionality found in traditional power systems. The control layers include a resource scheduling layer composed of a security-constrained unit commitment, a balancing layer composed of a security-constrained economic dispatch, and a regulation layer. The proposed method is validated by a set of numerical simulations. The sequel to this paper submitted to the same issue provides a set of extensive results that demonstrate how power grid balancing operations systematically address VER integration

An Enterprise Control Assessment Method for Variable Energy Resource-Induced Power System Imbalances--Part II: Parametric Sensitivity Analysis

In recent years, renewable energy has developed to address energy security and climate change drivers. However, as energy resources, they possess a variable and uncertain nature that significantly complicates grid balancing operations. As a result, an extensive academic and industrial literature has developed to determine how much such variable energy resources (VERs) may be integrated and how to best mitigate their impacts. While certainly insightful with the context of their application, many integration studies have methodological limitations because they are case specific, address a single control function of the power grid balancing operations, and are often not validated by simulation. The prequel to this paper presented a holistic method for the assessment of power grid imbalances induced by VERs based upon the concept of enterprise control. This paper now systematically studies these power grid imbalances in terms of five independent variables: 1) day-ahead market time step; 2) real-time market time step; 3) VER normalized variability; 4) normalized day-ahead VER forecast error; and 5) normalized short-term VER forecast error. The systematic study elucidates the impacts of these variables and provides significant insights as to how planners should address these independent variables in the future

Fuzzy Logic Based Robust DVC Design of PWM Rectifier Connected to a PMSG WECS under wind/load Disturbance Conditions

Permanent Magnet Generator has been widely used in Variable-Speed Wind Energy Conversion System (VSWECS). Fuzzy Logic Control (FLC) of the generator side converter has the ability to have good regulation of the DC-link voltage to meet the requirements necessary to achieve optimal system operation, regardless of the disturbances caused by the characteristics of the drive train or some changes into the DC-load. The main focus of this paper is to present a model for a three-phase voltage source space vector pulse width modulation (SVPWM) rectifier which is connected to a PMSG in a wind turbine system, where a direct voltage control (DVC) using FLC based on voltage orientation strategy is used to control the mentioned rectifier. The control algorithm employs a fuzzy logic controller to effectively achieve a smooth control of DC-link voltage under wind/load perturbation conditions. Some simulation results, using Matlab/Simulink, are presented to show the effectiveness of the SVPWM rectifier Connected to a PMSG WECS with the proposed control strategy